JP2003013707A - Exhaust gas utilizing device in power generating equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas utilizing device with a high fuel heat utilization efficiency by utilizing the heat of middle temperature combustion exhaust gas in combination with heat of low temperature exhaust gas. SOLUTION: The middle temperature combustion exhaust gas is fed to the overheated part 2C of a boiler 2 to generate medium pressure overheated steam, the steam generated in the boiler 2 is fed to a medium pressure turbine 3 through a route 11 to drive the turbine, and turbine exhaust gas is fed to the overheated part 2C of the boiler 2 through a route 12. Low pressure steam after cooling generated by water-cooling the low pressure steam by a cooling device having a cooling outer casing 1B is led through a route 13 to the overheated part 2C of the boiler 2 in combination with turbine exhaust gas from the medium pressure turbine 3. By the low pressure overheated steam passed from the overheated part 2C through a passage 14, the low pressure turbine 4 is driven to drive a generator 5. The turbine exhaust gas is led to a condenser 16, and condensed water therefrom is fed to the preheat part 2A of the boiler 2 through a return route 18 by a medium pressure feed pump 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas utilization device in a power generation facility using an internal combustion engine.

A low-temperature (60-160 ° C.) heat source generated in power generation of a diesel engine and a gas engine in a power generation method utilizing exhaust heat, that is, a cooling heat and a medium temperature (200-
This is a method of efficiently generating power by using the combustion exhaust gas of an internal combustion engine at 600 ° C.) as a heat source, and further utilizing the exhaust heat of the power generation as a heat source for air conditioning equipment, which is attached to the above-mentioned main equipment.

[0003]

2. Description of the Related Art In power generation of a diesel engine and a gas engine generator, only moderate temperature (combustion exhaust gas temperature from an internal combustion engine: 200 to 600 ° C.) is used to generate steam in a boiler to generate power by a turbine. Is going.

[0004]

However, in this type of power generation, about half of the total exhaust heat is used, so the efficiency is not high.

Further, the low-temperature exhaust heat and the exhaust heat of the cylinder of the internal combustion engine have not been converted to electricity due to the fact that the temperature is too low and the scale is small, and at most they are used directly as a heat source for air conditioning. It is only about.

Therefore, an object of the present invention is to use the heat of exhaust gas to the maximum extent by utilizing not only medium temperature combustion exhaust gas but also low temperature exhaust heat in a power generation facility using an internal combustion engine. Therefore, it is to provide an exhaust gas utilization device with high heat utilization efficiency as a whole.

[0007]

SUMMARY OF THE INVENTION The present invention has the following features to solve the above problems.

<Invention of Claim 1> In a power generation facility having an internal combustion engine having a liquid cooling engine, a boiler, an intermediate pressure turbine and a low pressure turbine connected to the generator, and condensate attached to the low pressure turbine. And a pump that supplies condensed water from the condenser to the boiler, and sends intermediate-temperature combustion exhaust gas generated from the internal combustion engine to the boiler to generate intermediate-pressure superheated steam, and by the steam generated in this boiler, The medium pressure turbine is driven, the turbine exhaust is sent to the superheated part of the boiler together with the low pressure steam after cooling from the cooling device, and the low pressure turbine is driven by the low pressure superheated steam from the superheated part, An exhaust gas utilization device in a power generation facility, characterized in that turbine exhaust gas is returned to the boiler by the pump via the condenser.

(Operation) It is known to generate electricity by using the intermediate temperature combustion exhaust gas generated from an internal combustion engine such as a diesel engine or a gas engine. However, in the present invention, the medium-temperature combustion exhaust gas is sent to the superheater section of the boiler to generate intermediate-pressure superheated steam, and the steam generated in this boiler drives the intermediate-pressure turbine, and the turbine exhaust gas is cooled by being attached to the internal combustion engine. It is sent to the superheated part of the boiler together with the low-pressure steam after cooling from the device, the low-pressure turbine is driven by the low-pressure superheated steam from this superheated part, and the turbine exhaust is returned to the boiler by the pump via the condenser. It was configured to do. Therefore, it is possible to utilize the exhaust heat of both of the medium-temperature combustion exhaust gas and the low-pressure steam after cooling from the cooling device, and moreover, since the low-pressure steam after cooling is passed through the superheated part of the boiler, it is sufficient. It is possible to generate electricity with high efficiency.

<Invention of Claim 2> The exhaust gas utilization apparatus in an internal-combustion-engine power generation facility according to claim 1, wherein the exhaust of the intermediate-pressure turbine and the low-pressure superheated steam are combined to drive the low-pressure turbine to generate electricity.

(Operation) The steam from the liquid cooling device is superheated by the low pressure steam superheater installed in the exhaust heat boiler, and this is sent to the low pressure turbine together with the exhaust of the intermediate pressure turbine. In cogeneration, the final exhaust is often used as a heat source, so the temperature of the condenser may be raised to use for full-scale air conditioning.To compensate for the decrease in power generation at this time, low-pressure steam is overheated to reduce the effective enthalpy difference. Increase to increase power generation. Since the condensing temperature can be set high, the heat source temperature of the absorption heat pump can be raised and the cogeneration efficiency can be increased.

<Invention of Claim 3> The exhaust gas utilization apparatus in an engine power generation facility according to claim 1, wherein the exhaust of the intermediate pressure turbine and the low pressure saturated steam are combined to drive the low pressure turbine to generate electricity.

(Operation) The low pressure saturated steam from the cooling device is
The low-pressure superheater is not needed because the low-pressure turbine generates electricity by supplying it to the low-pressure turbine together with the exhaust of the medium-pressure turbine that has generated power with superheated steam from the medium-temperature exhaust gas. In a small plant, even if the power generation efficiency is reduced, the components and the simplicity of operation are required. A device suitable for it can be provided.

<Invention of Claim 4> The operating pressure of the boiler is made equal to the steam pressure of the cooling device, and the steam generated from both is combined and passed through the superheat section to obtain low pressure superheated steam, and the low pressure turbine is driven to generate electricity. An exhaust gas utilization device in an internal combustion engine power generation facility according to claim 1.

(Operation) Since the generated steam has a low pressure,
No need for a medium pressure boiler. Boiler grows because of low pressure. On the other hand, the superheater, circulation pump, preheater, etc., may all be one unit. It is possible to provide a power recovery facility that is easy to operate and has a low facility cost. Medium size (1000-2000KW
Suitable for internal combustion engines

<Invention of Claim 5> One of the low-pressure turbine groups is an extraction turbine, and the extraction is used for another heat source.
The exhaust gas utilization device in a power generation facility according to claim 1, 2, 3, or 4, wherein the remainder is used for power generation.

(Operation) Since it is composed of a plurality of medium-pressure turbines and a plurality of low-pressure turbines, depending on the extraction pressure,
Within the temperature range of 80-140 ° C, the air is extracted and directly used for heating or heat source for driving heat pump to generate cold heat, and the remaining exhaust gas is led to a condenser to generate electricity to respond to changes in heat source for heat pump. You can build a system.

<Invention of Claim 6> A power generator operated by rotation of a main gear and a shaft having a pinion in mesh with the main gear in the middle are provided with coaxial impellers at both ends. The two-stage medium-pressure turbine and the two-stage low-pressure turbine provided with coaxial impellers at both ends of the shaft having a pinion in the middle in the circumferential direction of the main gear that meshes with each other. The intermediate pressure turbine and the low pressure turbine are driven to operate the generator, the intermediate pressure superheated steam is sequentially introduced into each stage of the intermediate pressure turbine, and the final exhaust and low pressure steam are combined, and then the superheated portion. The exhaust gas utilization device in the power generation facility according to claim 1, wherein the exhaust gas utilization device is configured to be sequentially fed to each stage of the low pressure turbines.

(Operation) The output of a general-purpose internal combustion engine for power generation of a diesel engine, a gas engine, etc. is 1000-40.
It is 00 kw, the output of the generator is 80 to 600 kw, and the turbine in this case is usually an impact type, but a blow-flow turbine is used, and by using in the form of claim 5, Highly efficient operation becomes possible.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

<First Embodiment> FIG. 1 shows a mode of power generation by a gas engine as an internal combustion engine 1.
Boiler 2 provided with preheating section 2A, evaporation section 2B, and superheating section 2C
The intermediate pressure turbine 3 and the low pressure turbine 4 connected to the generator 5, the condenser 16 attached to the low pressure turbine 4, and the condensed water from the condenser 16 are supplied to the boiler 2 via the return path 18. The submersible pressure supply pump 17 is provided.

In the gas engine, the fuel F and the air A are blown into the combustion chamber 1A and the piston is driven to obtain mechanical power. The intermediate-temperature combustion exhaust gas accompanying the mixed explosion of the fuel F and the air A is sent to the superheater 2C of the boiler 2 to generate intermediate-pressure superheated steam, and the steam generated in this boiler 2 is sent to the intermediate-pressure turbine 3 via the path 11. , And sends the turbine exhaust to the superheater 2C of the boiler 2 via the path 12.

At this time, the piston of the gas engine 1
The low-pressure steam after cooling, which is generated by water cooling with a cooling device including the cooling jacket 1B, is guided through a path 13, and is sent to the superheater 2C of the boiler 2 together with the turbine exhaust from the intermediate-pressure turbine 3. The low-pressure superheated steam from the superheater 2C drives the low-pressure turbine 4 through the path 14 to drive the generator 5, and the turbine exhaust gas is discharged to the condenser 16
The condensed water therefrom is supplied to the preheating section 2A of the boiler 2 by the intermediate pressure supply pump 17 through the return path 18.

In addition, a part of the condensed water from the condenser 16 is
Low-pressure supply pump 19 to cooling jacket 1B via return path 20
Supplied by.

<Second Embodiment> The present invention is different in the method of utilizing steam from the exhaust heat of an internal combustion engine, which will be described below.

A detailed example of this is shown in FIG. Although the basic configuration of the equipment is the same as that of claim 1, low-pressure steam superheating means is provided in the superheated portion of the boiler, low-pressure superheated steam is obtained through the steam from the cooling device through 13, and exhaust of the medium-pressure turbine from 12 is obtained. Together, they are guided to the low-pressure turbine 4 for power generation, and the exhaust steam is guided to the condenser 16 from 15 to obtain condensed water and recirculate it.

<Third Embodiment> A detailed example of this is shown in FIG. The basic configuration of the equipment is the same as that of claim 1, but the boiler has no means for superheating low-pressure steam, and saturated steam from the cooling device is not superheated and is combined with the exhaust 12 of the intermediate-pressure turbine through 13 to To the low pressure turbine 4,
Power is generated, and the exhaust steam is guided from 15 to the condenser 16 to obtain condensed water and recirculate it.

<Fourth Embodiment> FIG. 4 shows a detailed example of this. The basic configuration of the equipment is the same as that of claim 1, but the drum 25 is provided to share the liquid separation operation of the steam of the exhaust heat boiler and the steam of the cooling device to generate low-pressure steam, which is supplied to the boiler heating section 2C. It is led and supplied to the low pressure turbines 4-1 and 4-2. The exhaust treatment is the same as in the fourth embodiment.

<Fifth Embodiment> In the fifth embodiment shown in FIG. 5 shown as an application of the first embodiment, the low-pressure turbine 4 is used as an extraction turbine, and the extraction feeling in the middle is sent to the extraction condenser 23. , The heat can be used for other heat sources. For example, it can be used as a driving heat source for obtaining hot water and cold heat required for air conditioning and process industries. For example, the operating temperature (condensing temperature) is set to two operating temperatures of 80 ° C. and 65 ° C., and 80 ° C. generates cold heat.
5 ° C can be used for hot water production and air conditioning. Further, the exhaust gas of the final turbine can be used only for power generation with a condensing temperature of 45 ° C. It is desirable to select the extraction amount according to the demand for cold heat and electric power.

<Sixth Embodiment> The turbine shown in FIGS. 6 to 8 can be preferably used. That is, the generator 5 that operates by the rotation of the main gear 50
1, a two-stage intermediate pressure turbine 62, 63 provided with coaxial impellers 61 at both ends of a shaft having a pinion 60 meshing with the main gear 50 in the middle, and the main gear 50 Two-stage low-pressure turbines 72, 73 provided with coaxial impellers (not shown) are provided at both ends of a shaft having a pinion 70 in the middle that meshes at other positions in the circumferential direction. In the embodiment, the low pressure turbines 74 and 75 are further provided. The generator 51 is operated by driving these turbines 62, 63, 72, 73, and 74, 75.

As shown in FIG. 8, for example, when the medium pressure turbines 62, 63 are taken as an example, steam is sent to the first stage intermediate pressure turbine 62, and the exhaust steam is fed to the second stage intermediate pressure turbine. It is driven while sending steam to the turbine 63.

Thus, as described above, the medium-pressure superheated steam is sequentially introduced into the medium-pressure turbines 62 and 63, and the final exhaust gas,
In the embodiment, the exhaust gas of the intermediate-pressure turbine 63 and the low-pressure steam are combined and then sent to the superheated portion, and then the low-pressure turbines 7
2, 73, and 74, 75 are sequentially sent to each stage.

The embodiment of FIG. 6 has been described according to the fifth embodiment shown in FIG. 5, but it is obvious that it can be applied to other embodiments as it is. The number of medium-pressure turbines and / or low-pressure turbines can be plural as well as single.

[0034]

(Example) (Example 1) By the method of claim 1 (medium pressure reheat / low pressure overheat), 3045 kW with city gas of fuel 13A
The two gas engines were operated to recover electric power. That is, 31300 kg / h combustion exhaust gas at a temperature of 400 ° C. and saturated steam 5540 at a pressure of 0.4 MPa from cylinder cooling.
Waste heat of kg / h was used. Exhaust gas medium pressure superheated area 1
50m ² , mixed heating area 180m ² , evaporation section 400m
^2, placed in a 2 group boiler having a preheating section 300 meters ² of,
2000 kg / of superheated steam at a pressure of 1.0 MPa and 300 ° C
After obtaining hr, it is put into a blow-flow turbine connected to a generator to generate electricity, the turbine exhaust merges with the low-pressure steam from the cylinder cooling device, and is supplied to the low-pressure superheated part of the boiler. Power generation was performed at 0 ° C. to obtain a power generation amount of 1052 kW. This has an output efficiency of 41.0% as compared to the power generation amount of the gas generator of 6090 kW (generator output efficiency of 35%), and was able to recover electric power more efficiently than the conventional method.

(Embodiment 2) Exhaust gas and steam are the same as in Embodiment 1 by the method of claim 2 (low pressure / medium pressure independent heating),
Exhaust gas has a medium pressure superheating area of 150 m ² and a low pressure superheating area of 1
80 m ² , evaporating section 415 m ² , preheating section 490 m ² × 2
Put in a boiler with a base, pressure 1.0MPa, 300
℃ superheated steam 3000kg / h is obtained and put into a turbine connected to a generator to generate steam, and turbine exhaust is 0.3MPa steam from a cylinder cooling device 5300kg / h
Is heated to 185 ° C in the low pressure superheat section, mixed with medium pressure superheated steam and supplied to the low pressure turbine, and the final exhaust power is set to 0.3 Mp.
Generate 5kW of power and put in a condenser at 65 ℃, 60 ℃, 1
6 MJ / h of hot water was obtained and used for heating.

(Embodiment 3) Using the gas engine power generator of Embodiment 1, the method of claim 3 (medium pressure overheating / low pressure non-overheating)
To recover the power. That is, 2 at a medium pressure of 1.0 MPa
Superheated steam of 900 kg / h and 300 ° C was obtained and supplied to a medium-pressure turbine to make exhaust pressure 0.2 MPa, while low-pressure steam from the cylinder exhaust heat cooling device was 5700 kg / h.
To obtain 8700 kg / h of steam and supply it to a low-pressure turbine, exhaust pressure of 0.8 MPa, condensing temperature of 89 ° C., absorption heat pump driving heat source of 7 ° C., cold 12 MJ
/ H and power of 650 kW were obtained.

(Embodiment 4) Using the gas engine power generator of Embodiment 1, electric power was recovered by the method of claim 4 (low pressure evaporation, low pressure overheating). That is, the low pressure superheated area 200
m ^2, evaporators 380 m ^2, using a preheating unit 650 meters ^2, 0.4 M of the pressure at the exhaust heat of from the generator exhaust and cylinder
8030 kg / h of low pressure steam of pa was obtained, heated to 250 ° C., supplied to a turbine and condensed at 0.01 Mpa to obtain a power generation amount of 950 kW.

[0038]

As described above, according to the present invention, not only medium-temperature combustion exhaust gas but also low-temperature exhaust heat can be used in combination, and extraction in a low pressure range is possible. It is possible to obtain the exhaust gas utilization device with high heat utilization efficiency as a whole by maximally utilizing the existing heat and effectively utilizing the final condensed steam.

[Brief description of drawings]

FIG. 1 is a flow sheet of a first embodiment.

FIG. 2 is a flow sheet of a second embodiment.

FIG. 3 is a flow sheet of a third embodiment.

FIG. 4 is a flow sheet of a fourth embodiment.

FIG. 5 is a flow sheet of a fifth embodiment.

FIG. 6 is an explanatory diagram of a turbine configuration used.

FIG. 7 is a schematic perspective view of the turbine configuration used.

FIG. 8 is an explanatory diagram of a flow turbine configuration.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 1A ... Combustion quality, 1B ... Cooling mantle, 2 ... Boiler, 2A ... Preheating part, 2B ... Evaporating part, 2C ... Superheating part, 3
… Medium pressure turbine, 4… Low pressure turbine, 5… Generator, 16
... condenser, 17 ... submersible pressure supply pump, 18 ... return path, 1
9 ... Low-pressure supply pump, 23 ... Extraction condenser, 25-
Drum, 50 ... Main gear, 51 ... Generator, 60 ... Pinion, 61 ... Impeller, 62, 63 ... Medium pressure turbine,
72, 73, 74, 75 ... Low-pressure turbine.

Claims (6)

[Claims] 1. A power generation facility including an internal combustion engine having a cooling device, a boiler, a medium-pressure turbine and a low-pressure turbine connected to the generator, a condenser attached to the low-pressure turbine, and a condenser. A pump for supplying condensed water to the boiler is provided, medium-temperature combustion exhaust gas generated from the internal combustion engine is sent to the boiler to generate intermediate-pressure superheated steam, and the intermediate-pressure turbine is driven by the generated steam in the boiler, The turbine exhaust is sent to the superheated part of the boiler together with the low pressure steam after cooling from the cooling device, the low pressure turbine is driven by the low pressure superheated steam from the superheated part, and the turbine exhaust is the condenser. An exhaust gas utilization device in a power generation facility, characterized in that the pump is returned to the boiler via the pump. 2. The exhaust gas utilization apparatus in power generation equipment according to claim 1, wherein the exhaust of the intermediate pressure turbine and the low pressure superheated steam are combined to drive the low pressure turbine to generate electric power. 3. An exhaust gas utilization apparatus for power generation equipment according to claim 1, wherein the exhaust of the intermediate pressure turbine and the low pressure saturated steam are combined to drive the low pressure turbine to generate electric power. 4. The steam of the boiler and the steam of the cooling device are made to have the same pressure, and the steam generated from both is combined and passed through the superheat section to obtain low pressure superheated steam to drive the low pressure turbine to generate electricity. Exhaust gas utilization device in the power generation equipment of 1. 5. An exhaust gas utilization device in a power generation facility according to claim 1, 2, 3, or 4, wherein one of the low-pressure turbine groups is an extraction turbine, and is used as another heat source depending on a feeling of extraction on the way. 6. A two-stage intermediate pressure turbine provided with coaxial impellers at both ends of a shaft that has a generator that operates by rotation of a main gear and a pinion that meshes with the main gear in the middle. And a two-stage low-pressure turbine provided with coaxial impellers at both ends of a shaft having a pinion in the middle that meshes at other positions in the circumferential direction of the main gear. By driving the low-pressure turbine, the generator is operated, medium-pressure superheated steam is sequentially introduced into each stage of the medium-pressure turbine, the final exhaust and low-pressure steam are combined, and then sent to the superheat section, and then each low-pressure turbine. 5. A structure for sequentially sending to each stage of
An exhaust gas utilization device in the power generation facility according to any one of 1.